Pub Date : 2021-04-29DOI: 10.1080/07315171.2021.1923119
A. Singh, S. Singh
Abstract The present study reveals that ZrO2 MOS capacitor has been fabricated by RF sputtering technique. The maximum refractive index has been found to be 2.29 at 400 °C. From capacitance-voltage graph, it has been observed that the memory window and accumulation capacitance has been found to be maximum at 400 °C. The maximum memory window and accumulation capacitance has been found to be 0.50 V and 7.00 ×10−11 F, respectively. The flat band voltage shifts toward positive side at all temperatures. From current-voltage curve, it has been observed that the leakage current is found to be low at 400 °C and it is order of 10 − 7A at +20 V.
{"title":"Effect of annealing temperature on electrical properties of Al/ZrO2/p-Si MOS capacitor","authors":"A. Singh, S. Singh","doi":"10.1080/07315171.2021.1923119","DOIUrl":"https://doi.org/10.1080/07315171.2021.1923119","url":null,"abstract":"Abstract The present study reveals that ZrO2 MOS capacitor has been fabricated by RF sputtering technique. The maximum refractive index has been found to be 2.29 at 400 °C. From capacitance-voltage graph, it has been observed that the memory window and accumulation capacitance has been found to be maximum at 400 °C. The maximum memory window and accumulation capacitance has been found to be 0.50 V and 7.00 ×10−11 F, respectively. The flat band voltage shifts toward positive side at all temperatures. From current-voltage curve, it has been observed that the leakage current is found to be low at 400 °C and it is order of 10 − 7A at +20 V.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75032287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-29DOI: 10.1080/07315171.2021.1923117
A. Bhandari, N. S. Panwar
Abstract Thin films of [Ta2O5]1-x-[TiO2]x, with x = 0.08, were deposited on quartz substrates (for optical study) and p- type mono- crystalline silicon (100) surfaces (for structural characterization and electrical measurements) by RF magnetron sputtering of [Ta2O5]0.92-[TiO2]0.08, ceramic target, using argon as sputtering gas and oxygen as reactive gas. Films were deposited at room temperature and further annealed at 400, 500, 600 and 700 0C, at ambient atmosphere. The observed XRD patterns show that the as- deposited and annealed films have crystalline structure. The spectral transmissions of the [Ta2O5]1-x-[TiO2]x (x = 0.08) films were measured in UV-visible range. The low optical transmittance in as-deposited films may be due to the presence of unreacted tantalum along with Ta2O5 in the films. From the observed transmission spectra, refractive index, optical band gap, absorption coefficient, extinction coefficient, and thickness of prepared [Ta2O5]0.92-[TiO2]0.08 films, have been calculated by Swanepoel’s envelope technique.
{"title":"Optical properties of [Ta2O5]1-x[TiO2]x, (x = 0.08) thin films","authors":"A. Bhandari, N. S. Panwar","doi":"10.1080/07315171.2021.1923117","DOIUrl":"https://doi.org/10.1080/07315171.2021.1923117","url":null,"abstract":"Abstract Thin films of [Ta2O5]1-x-[TiO2]x, with x = 0.08, were deposited on quartz substrates (for optical study) and p- type mono- crystalline silicon (100) surfaces (for structural characterization and electrical measurements) by RF magnetron sputtering of [Ta2O5]0.92-[TiO2]0.08, ceramic target, using argon as sputtering gas and oxygen as reactive gas. Films were deposited at room temperature and further annealed at 400, 500, 600 and 700 0C, at ambient atmosphere. The observed XRD patterns show that the as- deposited and annealed films have crystalline structure. The spectral transmissions of the [Ta2O5]1-x-[TiO2]x (x = 0.08) films were measured in UV-visible range. The low optical transmittance in as-deposited films may be due to the presence of unreacted tantalum along with Ta2O5 in the films. From the observed transmission spectra, refractive index, optical band gap, absorption coefficient, extinction coefficient, and thickness of prepared [Ta2O5]0.92-[TiO2]0.08 films, have been calculated by Swanepoel’s envelope technique.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81607466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-28DOI: 10.1080/07315171.2021.1923121
Juhyun Yoo, Jongmyung Im, In-Seok Yu
Abstract In this study, for developing the low temperature sintering ceramics for speaker using piezoelectric actuator, Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 [PMW-PNN-PZT] ceramics doped with PbO, CuO, and WO3 as sintering aids were manufactured, and their microstructural, dielectric, and piezoelectric properties were investigated. At 0.3 wt% tungsten oxide (=WO3) added specimen sintered at 920 °C, the maximum values of piezoelectric properties were shown, respectively: the dielectric constant (εr) of 2275, piezoelectric constant (d33) of 502 pC/N, electromechanical coupling factor (kp) of 0.644, and mechanical quality factor (Qm) of 57 were suitable for the device application such as haptic display actuator using low temperature sintering multilayer ceramics.
{"title":"Physical properties of Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 ceramics doped with tungsten oxide for haptic display actuator","authors":"Juhyun Yoo, Jongmyung Im, In-Seok Yu","doi":"10.1080/07315171.2021.1923121","DOIUrl":"https://doi.org/10.1080/07315171.2021.1923121","url":null,"abstract":"Abstract In this study, for developing the low temperature sintering ceramics for speaker using piezoelectric actuator, Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 [PMW-PNN-PZT] ceramics doped with PbO, CuO, and WO3 as sintering aids were manufactured, and their microstructural, dielectric, and piezoelectric properties were investigated. At 0.3 wt% tungsten oxide (=WO3) added specimen sintered at 920 °C, the maximum values of piezoelectric properties were shown, respectively: the dielectric constant (εr) of 2275, piezoelectric constant (d33) of 502 pC/N, electromechanical coupling factor (kp) of 0.644, and mechanical quality factor (Qm) of 57 were suitable for the device application such as haptic display actuator using low temperature sintering multilayer ceramics.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89800951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-26DOI: 10.1080/07315171.2020.1810983
Shilpa Kumari, R. Rai, Pawan Kumar, P. Kumari, A. Dronov
Abstract In this article, we report the results of the Rietveld and impedance analysis of Eu doped La1–xEuxMnO3 (LEMO; x = 0.10, 0.30, and 0.50) perovskite manganites synthesized by solid-state reaction method. Structural studies through Rietveld analysis confirm that a mixed-phase nature of all LEM samples having a hexagonal unit cell structure with a less detectable impurity (Eu2O3) ceramics. The patterns are zanalyzed in detail with structural distortion and strain in LEM manganites ceramics. Dielectric constant and modulus are found to increase with increasing Eu concentration. The samples LEM-0.10 shows the negative capacitance at low frequency and temperature, respectively.
{"title":"Rietveld analysis and negative dielectric behavior of perovskite-like La1–xEuxMnO3 system","authors":"Shilpa Kumari, R. Rai, Pawan Kumar, P. Kumari, A. Dronov","doi":"10.1080/07315171.2020.1810983","DOIUrl":"https://doi.org/10.1080/07315171.2020.1810983","url":null,"abstract":"Abstract In this article, we report the results of the Rietveld and impedance analysis of Eu doped La1–xEuxMnO3 (LEMO; x = 0.10, 0.30, and 0.50) perovskite manganites synthesized by solid-state reaction method. Structural studies through Rietveld analysis confirm that a mixed-phase nature of all LEM samples having a hexagonal unit cell structure with a less detectable impurity (Eu2O3) ceramics. The patterns are zanalyzed in detail with structural distortion and strain in LEM manganites ceramics. Dielectric constant and modulus are found to increase with increasing Eu concentration. The samples LEM-0.10 shows the negative capacitance at low frequency and temperature, respectively.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84149422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-26DOI: 10.1080/07315171.2020.1810982
T. Liebsch, V. Sobolev
Abstract A theoretical analysis of the internal structure of interphase boundaries separating domains of coexisting phases is presented for the perovskite ferroelectric BaTiO3. The temperature dependence of interphase boundary widths and surface energies are calculated and compared with the corresponding parameters for different types of domain walls existing within the ferroelectric phases of BaTiO3.
{"title":"Coexistence of phases and interphase boundaries in BaTiO3","authors":"T. Liebsch, V. Sobolev","doi":"10.1080/07315171.2020.1810982","DOIUrl":"https://doi.org/10.1080/07315171.2020.1810982","url":null,"abstract":"Abstract A theoretical analysis of the internal structure of interphase boundaries separating domains of coexisting phases is presented for the perovskite ferroelectric BaTiO3. The temperature dependence of interphase boundary widths and surface energies are calculated and compared with the corresponding parameters for different types of domain walls existing within the ferroelectric phases of BaTiO3.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77838883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-26DOI: 10.1080/07315171.2020.1810986
R. Potong, R. Rianyoi, A. Chaipanich
Abstract The 0-3 connectivity lead-free barium calcium stannate titanate (BCTS)-Portland cement (PC) composites were produced by pressing and curing techniques. The effect of BCTS ceramic content on microstructure and dielectric properties of composites were studied. Scanning electron microscope images at the interfacial zone of composites showed denser microstructure between Portland cement matrix and BCTS ceramic. The dielectric constant and dielectric loss of BCTS-Portland cement composites were also found to depend on the frequency in the range tested. The dielectric results indicate that the BCTS ceramic can improve the dielectric constant (lower dielectric loss) in composites. The dielectric constant followed the cube model.
{"title":"Microstructure and dielectric properties of 0-3 connectivity lead-free BCTS-Portland cement composites","authors":"R. Potong, R. Rianyoi, A. Chaipanich","doi":"10.1080/07315171.2020.1810986","DOIUrl":"https://doi.org/10.1080/07315171.2020.1810986","url":null,"abstract":"Abstract The 0-3 connectivity lead-free barium calcium stannate titanate (BCTS)-Portland cement (PC) composites were produced by pressing and curing techniques. The effect of BCTS ceramic content on microstructure and dielectric properties of composites were studied. Scanning electron microscope images at the interfacial zone of composites showed denser microstructure between Portland cement matrix and BCTS ceramic. The dielectric constant and dielectric loss of BCTS-Portland cement composites were also found to depend on the frequency in the range tested. The dielectric results indicate that the BCTS ceramic can improve the dielectric constant (lower dielectric loss) in composites. The dielectric constant followed the cube model.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75011884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-26DOI: 10.1080/07315171.2020.1810984
Ashutosh Kumar Singh, Chandravilash Rai, S. Singh
Abstract BiFeO3 (BFO) and ZrO2 have been deposited on p-type (100) silicon substrate by sol-gel process and rf sputtering method, respectively. Metal-ferroelectric-insulator-semiconductor capacitor has been fabricated with 100 nm BFO and 10 nm ZrO2 shows maximum memory window of 1.54 V as compared to other fabricated capacitors with 5 and 15 nm insulating layer thickness. Improvement in current density has been also observed in different thickness of buffer layer of MFIS capacitors. The improved current density of order of 10-7 A/cm2 has been observed in MF(100nm)I(10nm)S structure. It has been also observed in MF(100nm)I(10nm)S structure that no charge value degrades up to 1011 iteration cycles.
{"title":"Effect of insulator layer thickness on electrical properties of Al/BiFeO3/ZrO2/p-Si for nonvolatile memory applications","authors":"Ashutosh Kumar Singh, Chandravilash Rai, S. Singh","doi":"10.1080/07315171.2020.1810984","DOIUrl":"https://doi.org/10.1080/07315171.2020.1810984","url":null,"abstract":"Abstract BiFeO3 (BFO) and ZrO2 have been deposited on p-type (100) silicon substrate by sol-gel process and rf sputtering method, respectively. Metal-ferroelectric-insulator-semiconductor capacitor has been fabricated with 100 nm BFO and 10 nm ZrO2 shows maximum memory window of 1.54 V as compared to other fabricated capacitors with 5 and 15 nm insulating layer thickness. Improvement in current density has been also observed in different thickness of buffer layer of MFIS capacitors. The improved current density of order of 10-7 A/cm2 has been observed in MF(100nm)I(10nm)S structure. It has been also observed in MF(100nm)I(10nm)S structure that no charge value degrades up to 1011 iteration cycles.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77973229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-26DOI: 10.1080/07315171.2020.1832393
Y. Gan, W. Cao
Abstract The dielectric constant measured by the LCR-meter is a differential-type, and is not equivalent to capacitivity. Capacitivity of ferroelectrics is the dielectric constant corresponding to electric hysteresis loop. Two kinds of dielectric constants are investigated based on the P-E loop mechanisms: turning effect of dipoles toward electric field direction, electric field-induced polarization effect, and dipole coupling effect. Numerical simulation of the theoretic equations exhibit adouble-peak of the differential dielectric constant, in which the distance between the two peaks depends on the temperature and the electric field. A much narrow static dielectric constant peak and negative peak appear corresponding to the loop. Mechanisms are analyzed schematically in detail. HIGHLIGHTS Definitions of differential- and static-dielectric constant are introduced and compared. Theoretic equations for the two dielectric constants are derived from the three effects. Variations of the two dielectric constants with E and T are demonstrated schematically. Mechanisms of the variations are explained in detail.
{"title":"Mechanism analyses of differential and static dielectric constants in ferroelectrics","authors":"Y. Gan, W. Cao","doi":"10.1080/07315171.2020.1832393","DOIUrl":"https://doi.org/10.1080/07315171.2020.1832393","url":null,"abstract":"Abstract The dielectric constant measured by the LCR-meter is a differential-type, and is not equivalent to capacitivity. Capacitivity of ferroelectrics is the dielectric constant corresponding to electric hysteresis loop. Two kinds of dielectric constants are investigated based on the P-E loop mechanisms: turning effect of dipoles toward electric field direction, electric field-induced polarization effect, and dipole coupling effect. Numerical simulation of the theoretic equations exhibit adouble-peak of the differential dielectric constant, in which the distance between the two peaks depends on the temperature and the electric field. A much narrow static dielectric constant peak and negative peak appear corresponding to the loop. Mechanisms are analyzed schematically in detail. HIGHLIGHTS Definitions of differential- and static-dielectric constant are introduced and compared. Theoretic equations for the two dielectric constants are derived from the three effects. Variations of the two dielectric constants with E and T are demonstrated schematically. Mechanisms of the variations are explained in detail.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81183310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-26DOI: 10.1080/07315171.2020.1810985
S. Thakur, Mamta Shandilya, M. Graça, M. Valente
Abstract Barium Zirconate Titanate-Barium Calcium Titanate (BCT-BZT) is one of the lead-free systems, which exhibits remarkable ferroelectric properties akin to lead-based perovskite materials. In this study, we have synthesized x(Ba0.85Ca0.15)TiO3-(1−x)Ba(Zr0.15Ti0.85)O3 (where x = 0.4, 0.5, 0.6) monophonic powders by hydrothermal method at 150 °C. X-ray diffraction reveals the pure tetragonal phase. Scanning electron microscopy (SEM) studies make known that the crystal growth is uniform due to low temperature, and that the ceramics are highly dense and polycrystalline. The single semicircle indicates bulk behavior. The bulk resistance decreases with the increase in temperature showing a typical semiconducting property, negative temperature coefficient of resistance (NTCR) behavior.
{"title":"To study the effect of low temperature crystal growth on the structural and ferroelectric properties of lead-free BCT-BZT ceramic","authors":"S. Thakur, Mamta Shandilya, M. Graça, M. Valente","doi":"10.1080/07315171.2020.1810985","DOIUrl":"https://doi.org/10.1080/07315171.2020.1810985","url":null,"abstract":"Abstract Barium Zirconate Titanate-Barium Calcium Titanate (BCT-BZT) is one of the lead-free systems, which exhibits remarkable ferroelectric properties akin to lead-based perovskite materials. In this study, we have synthesized x(Ba0.85Ca0.15)TiO3-(1−x)Ba(Zr0.15Ti0.85)O3 (where x = 0.4, 0.5, 0.6) monophonic powders by hydrothermal method at 150 °C. X-ray diffraction reveals the pure tetragonal phase. Scanning electron microscopy (SEM) studies make known that the crystal growth is uniform due to low temperature, and that the ceramics are highly dense and polycrystalline. The single semicircle indicates bulk behavior. The bulk resistance decreases with the increase in temperature showing a typical semiconducting property, negative temperature coefficient of resistance (NTCR) behavior.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81136843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-24DOI: 10.1080/07315171.2020.1799628
S. Ai, Shao-yin Zhang, Jin-Song Wang, Yuan-Zhen Cai
Abstract From the view-point of non-equilibrium (or irreversible) statistical thermodynamics, the similarities and differences between the processes of (first-order) ferroelectric phase transition and those of ferroic hysteresis were compared. They are all irreversible. The former are local and rate-dependent, at the meanwhile, the latter are non-local and rate-independent.
{"title":"Rational analysis of processes of (first-order) ferroelectric phase transition and those of ferroic hysteresis","authors":"S. Ai, Shao-yin Zhang, Jin-Song Wang, Yuan-Zhen Cai","doi":"10.1080/07315171.2020.1799628","DOIUrl":"https://doi.org/10.1080/07315171.2020.1799628","url":null,"abstract":"Abstract From the view-point of non-equilibrium (or irreversible) statistical thermodynamics, the similarities and differences between the processes of (first-order) ferroelectric phase transition and those of ferroic hysteresis were compared. They are all irreversible. The former are local and rate-dependent, at the meanwhile, the latter are non-local and rate-independent.","PeriodicalId":50451,"journal":{"name":"Ferroelectrics Letters Section","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81593383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}